JP2534065B2 - Recording material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a recording material using a color-producing phthalide compound capable of obtaining an image having absorption even in a near infrared region in heat-sensitive, pressure-sensitive or laser recording. It is about.

[Prior art]

The pressure-sensitive recording material generally utilizes a chemical reaction between a substantially colorless leuco dye and a color former capable of forming a colored image by coloring the leuco dye upon contact. Specifically, a color former sheet coated with a microencapsulated solution of a leuco dye in an organic solvent and a color former sheet coated with a color former together with a binder are superimposed on each other, and from the back. The color capsule is broken by pressing or the like to cause a color reaction.

The heat-sensitive recording material is a material in which a leuco dye and a color former are supported on a support, and gives a color-developed image when an image signal is given thermally by a minute heating element.

Such a pressure-sensitive and heat-sensitive recording paper can be shortened by a relatively simple device without performing complicated processing such as development and fixing in comparison with other recording materials such as electrophotography and electrostatic recording material. It is used in various fields because records can be obtained in time. As a leuco dye of such a recording material, a blue dye typified by crystal violet lactone, leuco crystal violet, a black dye typified by a fluoran compound substituted by 7-anilino, and the like are mainly used. In recent years, optical character readers and readers for label bar codes have been developed, and the usage rate thereof has been increasing. In these devices, light sources such as light emitting diodes and light wavelengths using semiconductor radar are used. Light sources above 700 nm are also commonly used. However, since the blue dye and the black dye have almost no light absorption in the near infrared region of 750 nm or more, the color reading cannot be performed by the reading device. Therefore, there is a strong demand for new development of a leuco dye having a light-absorbing wavelength of 750 nm or more in a color developing body.

Such leuco dyes are disclosed, for example, in JP-A-51-121035.
JP-A-51-121037, JP-A-51-121038, JP-A-51-121038
57-167979, JP-A-58-157779, JP-A-60-226871
No. 60-230890, 60-231766, and
61-22076, JP-A-61-165380, JP-A-61-166856
No., etc.

However, these leuco dyes do not show sufficient long-wavelength absorption ability, and even if they have long-wavelength absorption ability, many of them have weak absorption ability, and further show excellent absorption ability at long-wavelength. The thing has a problem that it is colored from yellow to orange, is inferior in storability, or has a background fog.
The current situation is that nothing satisfactory has been obtained yet.

〔Purpose〕

An object of the present invention is to provide a novel recording material containing a color-forming phthalide compound having a strong absorption in the near infrared region of 750 nm or more as a color-forming component.

〔Constitution〕

According to the present invention, there is provided a recording material containing at least one basic colorless dye represented by the following general formula (I).

R ₁ , R ₂ ; hydrogen, alkyl group R ₃ ; hydrogen, alkyl group, halogen R ₄ ; hydrogen, alkyl group, alkylamino group, dialkylamino group, cyclic amino group, alkyl group, halogen R ₅ , R ₆ ; alkyl Group, cycloalkyl group, n; integer of 4 to 6) The basic colorless dye of the general formula (I) used in the present invention is usually a white or light colored powder, and 750 nm or more by contact with a color developer. Shows strong absorption in the near infrared region of 400 ~
It shows almost no absorption in the visible region of 700 nm. Therefore, although it is impossible to visually confirm the image, there is a feature that the image is recognized only by an optical character reading device using a light emitting diode or a semiconductor laser as a light source. Therefore, the heat-sensitive recording material of the present invention has an arbitrary color tone (color tone unique to the basic dye used in combination) by optionally using other basic dyes in combination, and has a near-infrared light of 750 nm or more. Has absorption in the area.

Specific examples of the basic dye represented by the general formula (I) used in the present invention include the following.

In the present invention, the phthalide compound represented by the general formula [I] can be used in combination with other leuco dyes, and the leuco dye used in this case is generally known in this type of leuco recording material. The leuco dyes mentioned above are used. Specific examples of such leuco dyes include the followings.

3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6- Diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dimethylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluorane, 3-dimethylamino -5,7-Dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7 -Chlorfluorane, 3- (Np-tolyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3-pyrrolidino 6-Methyl-7-anilinofluorane, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylaminofluorane, 2- {3,6-bis (diethylamino) -9- (o -Chloranilino) xanthylbenzoic acid lactam}, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-butylamino-7- ( o-chloranilino) fluorane, 3-N-methyl-N-amylamino-6-methyl-7
-Anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N, N- Diethylamino) -5-methyl-7-
(N, N-dibenzylamino) fluorane, benzoyl leuco methylene blue, 6'-chloro-8'-methoxy-benzoindolino-
Pyrirospirane, 6'-bromo-3'-methoxy-benzoindolino-
Pyrirospirane, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl)- 3- (2'-methoxy-5'-nitrophenyl) phthalide, 3- (2'-hydroxy-4'-diethylaminophenyl) -3- (2'-methoxy-5'-methylphenyl) phthalide, 3- ( 2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-
Methylphenyl) phthalide, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7- (N -Benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluorane, 3-diethylamino-5-chloro-7- (α-phenylethylamino) fluorane, 3 -(N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluorane, 3-diethylamino-5-methyl-7- (α -Phenylethylamino) fluorane, 3-diethylamino-7-piperidi Fluoran, 2-chloro-3-(N-methyl torii Gino) -7-
(Pn-butylanilino) fluoran, 3- (N-benzyl-N-cyclohexylamino)-
5,6-Benz-7-α-naphthylamino-4′-bromofluorane 3-diethylamino-6-methyl-7-mesitidino-
4 ', 5'-benzofluorane and the like.

Further, as the coloring agent used in combination with the above-mentioned leuco dye in the present invention, various electron-accepting compounds which cause the above-mentioned leuco dye to develop color upon contact, or an oxidizing agent, etc. are applied.
Such substances are conventionally known, and specific examples thereof include the following inorganic acids, organic acids, phenolic substances, and phenol resins.

Bentonite, zeolite, acid clay, activated clay, silica gel, zinc oxide, zinc chloride, zinc bromide, aluminum chloride, salicylic acid, 3-tert-butylsalicylic acid, 3,
5-di-tert-butylsalicylic acid, di-m-chlorophenylthiourea, di-m-trifluoromethylphenylthiourea, di-phenylthiourea, salicylanilide, 4,
4'-isopropylidene diphenol, 4,4'-isopropylidenebis (2-chlorophenol), 4,4'-isopropylidenebis (2,6-dibromophenol), 4,4 '
-Isopropylidene bis (2,6-dichlorophenol), 4,4'-isopropylidene bis (2-methylphenol), 4,4'-isopropylidene bis (2,6-dimethylphenol), 4,4'- Isopropylidene bis (2-t
ert-butylphenol), 4,4'-sec-butylidene dipheceal, 4,4'-cyclohexylidenebisphenol, 4,4'-cyclohexylidenebis (2-methylphenol), 4-tert-butyl Phenol, 4-phenylphenol, 4-hydroxydiphenoxide, α-naphthol, β-naphthol, dimethyl 5-hydroxyphthalate, methyl-4-hydroxybenzoate, 4-hydroxyacetophenone, novolak-type phenol resin,
2,2'-thiobis (4,6-dichlorophenol), catechol, resorcin, hydroquinone, pyrogallol, phloroglysin, phloroglysincarboxylic acid, 4-tert-octylcatechol, 2,2'-methylenebis (4-chlorophenol) , 2,2'-methylenebis (4-methyl-6)
-Tert-butylphenol), 2,2-dihydroxydiphenyl, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate,
Benzyl p-hydroxybenzoate, p-hydroxybenzoic acid-p-chlorobenzyl, p-hydroxybenzoic acid-
o-chlorobenzyl, p-hydroxybenzoic acid-p-methylbenzyl, p-hydroxybenzoic acid-n-octyl, benzoic acid, zinc salicylate, 1-hydroxy-2-
Naphthoic acid, 2-hydroxy-6-naphthoic acid, zinc 2-hydroxy-6-naphthoate, 4-hydroxydiphenyl sulfone, 4,2'-diphenol sulfone, 4-hydroxy-4'-chlorodiphenyl sulfone, Screw (4
-Hydroxyphenyl) sulfide, 2-hydroxy-
p-toluic acid, zinc 3,5-di-tert-butylsalicylate, tin 3,5-di-tert-butylsalicylate, tartaric acid, oxalic acid, maleic acid, citric acid, succinic acid, stearic acid, 4-hydroxy Phthalic acid, boric acid, biimidazole, hexaphenylbiimidazole, carbon tetrabromide, methylenebis- (oxyethylenethio) diphenol, ethylenebis- (oxyethylenethio) diphenol, bis- (4-hydroxyphenylthioethyl) Ketone, bis- (4-hydroxyphenylthioethyl) ether, m
-Xylylene bis (4-vidroxyphenylthio) ether and the like.

In the present invention, when a leuco dye and a color former are bound and supported on a support to obtain a heat-sensitive recording material, various conventional binders can be appropriately used. In order to obtain a pressure-sensitive recording material, when an encapsulated leuco dye is supported on a support or a color developing agent is supported on a support, similarly various conventional binders can be appropriately used. Specific examples of such a binder include the followings.

Polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic acid amide / acrylic acid ester copolymer, acrylic acid amide / acrylic acid Other than water-soluble polymers such as ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc., Polyvinyl acetate, polyurethane, styrene / butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride / vinyl acetate copolymer, polybutylmethacrylate, ethylene / Vinyl acetate copolymer, styrene / butadiene / acrylic copolymer latex such as such.

Further, in the present invention, if necessary, an auxiliary additive component commonly used in this type of pressure-sensitive and heat-sensitive recording material, for example,
A filler, a surfactant, a heat-fusible substance, a lubricant, a pressure color-developing inhibitor and the like can be used in combination. In this case, as the filler, for example, other than inorganic fine powder such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium and silica, etc. , Urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and other organic fine powders. Examples of the lubricant include higher fatty acids and metal salts thereof, higher fatty acid amides, higher paper fatty acid esters, and animals. , Vegetable, mineral or petroleum waxes.

In the present invention, when the pressure-sensitive recording material is prepared, the color developing agent sheet is prepared by dispersing or dissolving the color developing agent in water or an organic solvent, adding a binder if necessary, and adding paper or the like. On the other hand, the color-developing agent sheet is prepared by dispersing the microencapsulated leuco dye with a suitable dispersant and coating it on a support such as paper. The microencapsulation in this case can be carried out by a conventionally known method such as the method described in USP 2800457.

On the other hand, when preparing a heat-sensitive recording material, a dispersion liquid of a leuco dye and a color developing agent, which are separately dispersed, is mixed with an appropriate binder, and this mixed liquid is applied onto a support such as paper.

In this case, the color-developing layer may be coated in one layer or two or more layers, or may be separately coated in a leuco dye layer and a developer layer. Further, an undercoat layer or a protective layer may be provided as is known in the heat-sensitive recording material.

According to the present invention, there is also provided a thermal transfer type heat-sensitive recording material in which a leuco dye and a color former are supported on different supports, but to prepare this, the leuco dye is dispersed or dissolved in water or a solvent. Then, a heat resistant sheet, for example, a polyester film is applied to a support to form a transfer sheet, while a color developing agent is dispersed or dissolved in water or a solvent and applied to the support to form a receiving sheet. .

The recording material of the present invention is used in various fields similar to the conventional ones, and in particular, by utilizing its excellent near-infrared light absorption property, for an optical character reader, a label bar coder, It can be used as a recording material for reading the record of a barcode reader.

When the recording material of the present invention is used as a thermosensitive recording label sheet, a thermosensitive coloring layer containing the above-mentioned leuco dye and a coloring agent is provided on one surface of the support, and an adhesive is provided on the other surface of the support. It may have a structure in which a release mount is provided via layers.

〔effect〕

The basic dye represented by the above general formula (I) used in the present invention has a strong image absorption at 750 nm or more, but since it is a substance having almost no absorption in the visible region, it should be contained. In the recording material of the present invention, the image is not visually recognized, but a general-purpose OCR (optical character reader) is used.
The image can be sufficiently recognized by an image reading device using a light source such as a light emitting diode or a semiconductor laser. Further, since the dye represented by the general formula (I) has almost no absorption in the visible region, for example, in the present invention, by combining this dye with another leuco dye,
It is possible to obtain a recording material having a strong absorption at 750 nm or more and an arbitrary color tone (color tone of the leuco dye used in combination).

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 Each mixture of the following preparation was dispersed by a ball mill,
[Solution A] and [Solution B] were adjusted.

[Liquid A]

3- (4-diphenylaminophenyl) -3- [1-
(P-Dimethylaminophenyl) -1-phenyl) -ethyleno-2] -6-dimethylaminophthalide 20 parts Polyvinyl alcohol 10% aqueous solution 10 parts Water 70 parts [B liquid] 2.2'-bis (4-hydroxyphenyl) Propane 60 parts Calcium carbonate 60 parts Polyvinyl alcohol 120 parts Water 60 parts [Solution A] and [Solution B] were mixed at a ratio of 1: 1 to obtain a heat-sensitive coating liquid. This is applied to a high-quality paper with a basis weight of 50 g / m ² and 0.5 g of dye solids
A thermal recording paper was obtained by coating and drying so as to be / m ² .

Example 2 In the [solution A] of Example 1, 3- (4-diphenylaminophenyl) -3- [1- (P-dimethylaminophenyl) -1-phenyl) ethyleno-2] -6-dimethylaminotali was prepared. Use 3- (4-di-P-toluylaminophenyl) -3- [1- (p-dimethylaminophenyl) -1-phenyl) -ethyleno-2] -6-dimethylaminophthalide instead of A heat-sensitive recording paper was obtained in the same manner as in Example 1 except that the heat-sensitive recording paper was used.

Example 3 A mixture having the following composition was dispersed by a ball mill to prepare [C liquid].

[C liquid]

3-diethylamino-7-chlorofluorane 20 parts 10% aqueous solution of polyvinyl alcohol 10 parts water 70 parts [A solution], [B solution] and [C] above in Example 1.
Liquid) in a ratio of 1: 2: 1 to prepare a heat-sensitive coating liquid, which is applied to high-quality paper with a basis weight of 50 g / m ² so that the solid content of the dye is 0.5 g / m ² and dried. Got the paper.

Example 4 In the [C liquid] of Example 3, 3-diethylamino-
Other than using 3-diethylamino-6-methyl-7-chlorofluorane instead of 7-chlorofluorane,
A thermal recording paper was obtained in the same manner as in Example 3.

Example 5 In the [C liquid] of Example 3, 3-diethylamino-
A thermosensitive recording paper was obtained in the same manner as in Example 3 except that crystal violet lactone was used instead of 7-chlorofluorane.

Example 6 In the [C liquid] of Example 3, 3-diethylamino-
A thermosensitive recording paper was obtained in the same manner as in Example 3 except that 3-diethylamino-5-methyl-7-dibenzylaminofluorane was used instead of 7-chlorofluorane.

Example 7 In the [C liquid] of Example 3, 3-diethylamino-
3-N-methyl-N instead of 7-chlorofluorane
A thermosensitive recording paper was obtained in the same manner as in Example 3 except that -cyclohexyl-6-methyl-7-anilinofluorane was used.

Example 8 In the [C liquid] of Example 3, 3-diethylamino-
A thermosensitive recording paper was obtained in the same manner as in Example 3 except that 3-dibutylamino-7- (o-chloroanilino) fluorane was used instead of 7-chlorofluorane.

Comparative Example 1 In the liquid A of Example 1, 3- (4-diphenylaminophenyl) -3- [1- (p-dimethylaminophenyl) -1-phenyl] -ethyleno-2] -6-dimethylaminophthalide was prepared. A thermosensitive recording paper was obtained in the same manner as in Example 1 except that crystal violet lactone was used instead of.

Comparative Example 2 A thermosensitive recording paper was obtained in the same manner as in Comparative Example 1 except that 3-diethylamino-7-chlorofluorane was used in place of Curstal Violet lactone in Comparative Example 1.

Comparative Example 3 A heat-sensitive material was prepared in the same manner as in Comparative Example 1 except that 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane was used in place of crystal violet lactone in Comparative Example 1. I got the recording paper.

The thermal paper obtained as described above was printed by a normal printer and colored, but the color tone and PCS value at 800 nm are shown in Table 1.
Shown in

As is clear from the results shown in Table 1, it is clear that the recording material of the present invention has a high PCS value in the near infrared region near 800 nm and can impart an arbitrary color tone.

Claims (1)

(57) [Claims] 1. A recording material containing at least one basic colorless dye represented by the following general formula (I). R ₁ , R ₂ ; hydrogen, alkyl group R ₃ ; hydrogen, alkyl group, halogen R ₄ ; hydrogen, alkyl group, alkylamino group, dialkylamino group, cyclic amino group, alkyl group, halogen R ₅ , R ₆ ; alkyl Group, cycloalkyl group, n; integer of 4 to 6)